Optimize the virtio-balloon feature on the ARM platform by adding
a variable to keep track of the current hot-plugged pc-dimm size,
instead of traversing the virtual machine's memory modules to count
the current RAM size during the balloon inflation or deflation
process. This variable can be updated only when plugging or unplugging
the device, which will result in an increase of approximately 60%
efficiency of balloon process on the ARM platform.
We tested the total amount of time required for the balloon inflation process
on ARM:
inflate the balloon to 64GB of a 128GB guest under stress.
Before: 102 seconds
After: 42 seconds
Signed-off-by: Qi Xi <xiqi2@huawei.com>
Signed-off-by: Ming Yang yangming73@huawei.com
---
hw/mem/pc-dimm.c | 2 ++
hw/virtio/virtio-balloon.c | 33 +++++----------------------------
include/hw/boards.h | 1 +
3 files changed, 8 insertions(+), 28 deletions(-)
diff --git a/hw/mem/pc-dimm.c b/hw/mem/pc-dimm.c
index 50ef83215c..192fc7922c 100644
--- a/hw/mem/pc-dimm.c
+++ b/hw/mem/pc-dimm.c
@@ -81,6 +81,7 @@ void pc_dimm_plug(PCDIMMDevice *dimm, MachineState *machine)
memory_device_plug(MEMORY_DEVICE(dimm), machine);
vmstate_register_ram(vmstate_mr, DEVICE(dimm));
+ machine->device_memory->dimm_size += vmstate_mr->size;
}
void pc_dimm_unplug(PCDIMMDevice *dimm, MachineState *machine)
@@ -90,6 +91,7 @@ void pc_dimm_unplug(PCDIMMDevice *dimm, MachineState *machine)
memory_device_unplug(MEMORY_DEVICE(dimm), machine);
vmstate_unregister_ram(vmstate_mr, DEVICE(dimm));
+ machine->device_memory->dimm_size -= vmstate_mr->size;
}